Method of dry cleaning and weatherproofing fabrics



United States Patent Ohio, a corporation No'DraWing. pp licatioh 11113 28, 1951,

Serial '-7 Claims.

This invention relates to *a =metho'd of 'dry cleaning fabrics :or --'garments are to be weathenproofed repellenc-y thereof; This in part of our copendihg filed August fabric, no continuous coating .1s utilized, that the screen pores were large enough naked eye.

purposes, although itfabric and is read These water rep which are weather-proof or *whieh witho'u't impairing the water application is a continuation application Serial l l'=l,-3 42,- 20

similar products exemplify the In the Water repellent types a h that the wires werecoat'ed with a .thin

would hold water even ,if the to be readily visible to the classifications, depending upon the permanence of :the

component.

There are many varieties of fabric of this general type and .many of or contrasted weatherproofing' is a ical synthesis of a are not matters of commoner-public In general these fabr'icsm' y be "compared with the Wax water coated fabrics the observaccornplished by the physical or chemrepellent compound with the textile fiber itself so that from'the point of view of the dry .cleaner the fiber water repellent fiber fiber coated may rather than as a water be regarded as an inherently receptive with solvent soluble wax.

Dry cleaning, however,

involves 2 or, alternatively, tosubject them in solvent-devoid of detergent.

Water repellent garments are almost :always outer garments and are, therefore, preferably :dry :cleaned rather than laundered :or wet cleaned, because the water washing :processes, generally, :so disarrange the fabrics and loosen their 'nap thatitrisdilficultor impossible -'to restore the garments to-original shape and feel :by the usual 'shingroperations. If theigannent iscleaned in straight solvent without detergent en it simply .is not thoroughly cleaned and the customer does "notobtain the resultwhich was anticipated.

The object of the present invention :is to provide-a method of drycleaningwater repellent -fabrics with a dry cleaning solvent containing a detergentwitho'ut sacrificing the inherent water repelleney of the fabric. further our object to -to partial dry cleaning less of whether or .not. it was re-impregnated with wax after the dry 'cleaning treatment.

our investigation has confirmed the heretofore unare inimica'l to'the wise be expected.

Dry cleaning detergents fall into two I v general classes; absorbefaments and soaps.

Absorbef acients I x v effective and widely used amongv the absorbefacients is a product known as mahogany s ll innate, its use being more specifically disclosed States .Patent No. 2,024,981, issued December filfhe dry cleaning soaps usually comprise potassium ate i.

fattyoils and-their salts, sulvated alcohols and alkylary-l sulphonates. Many admixtures of these bodies may be used alternatively as soaps without addition of tree Water 'or as absorbefacients to facilitate the addition of free water.

In any case, these bodies are,

. I V faw active a n I and are used as, surgents The efiicie cy of the dry cleaning of the-surface active materials.

More specifically, we have discovered that the ifects of'thesurface active agents may be nullified by impre natm-g 'the fabric with a metallic salt 'of the type of alumior an alcoholate of the type of aluminum Appropriate alcoholates have some advanthe salts in that many of them can be dissolved dry cleaning solvent whereas the salts cannot; but on the other hand, from the point of view of costs and of operating convenience in the average dry cleaning plant, it is more expedient at the present time to utilize the salts than the metal alcoholates.

Nonetheless, the use of salts poses a problem because while salts such as aluminum acetate may be soluble in water, they are not soluble in dry cleaning solvents. However, if an aqueous solution of aluminum acetate, or a like salt, is dispersed throughout the solvent, then the fabric immersed in the solvent will absorb both the water and the salt from the solvent. It is not easy to secure an appropriate dispersal or emulsion of aqueous aluminum acetate solution in solvent for the reason that most emulsifiers are in andof themselves surface active agents, and therefore tend to accentuate the deleterious effect of the traces of absorbefacient or detergent which remain after the dry cleaning. Also, an aqueous aluminum acetate solution is inherently more difficult to emulsify than water or most other solunum acetate propoxide. tages over directly in tions.

aluminum acetate solution which would lose their surface active properties on repellent properties of the wax.

We have made the discovery and determination that the salts of long chain amines and volatile organic acids, such as stearic amine acetate, have the requisite properties. These compounds are effective emulsifiers for aluminum acetate solutions in dry cleaning solvents. After drying on the fabric, and particularly after the heating to which the fabric is subjected during drying and pressing, these emulsifying agents decompose and have no surface activity which impairs the water resistance of the wax with which the fibers are impregnated and coated. If desired, mechanical dispersers or homogenizers may be used in place of emulsifiers, but such practice would involve the installation of extra equipment which in most dry cleaning plants would be used only occasionally. Further, if the dispersion is less than perfect, mottled or uneven weatherproofing is the likely consequence.

Thus, the preferred process of this invention involves the conventional dry cleaning of the garment in solvent with a surface active agent, then treatment with an aqueous dispersion or emulsion of a nullifying agent in dry cleaning solvent preferably with the assistance of a cationic type of emulsifying agent. If the dry cleaning has removed the water repellent component from the fabric it may be restored by contemporaneously, or thereafter, impregnating the garment with wax dissolved in a dry cleaning solvent.

Surprisingly, the fluid containing both nullifying and emulsifying agents has an appreciable though selective detergent efiect, although not of the surface active type. Hence it has been possible in practice to substitute the materials of our invention for a portion of the normal quantity of detergents employed in dry cleaning operations. Not only are the various surface active agents nullified, but they may in some cases be partially supplanted by our process.

In practicing the process of this invention, the garments are first subjected to a dry cleaning process with a cleaning solvent which contains a surface active agent of the type hereinbefore described. Of these surface active agents, mahogany sulfonates are the most effective from the point of view of dry cleaning, and hence most inimicable to effective weatherproofing. Therefore, the following example of the after treatment to eliminate the surface activity is provided in relation to fabrics which have been first dry cleaned with mahogany sulfonates.

To 106.5 lbs. of molten stearyl amine, We add 18.0 lbs. of glacial acetate acid and 25.5 lbs. of commercial oleic acid. The mixture is stirred until homogeneous. This is mixed by vigorous stirring with 46.7 lbs. of water. A heavy paste results which is allowed to cool to room temperature.

We then charge a ribbon-type powder mixer with 15.0 lbs. of dry basic aluminum acetate powder, 1.8 lbs. of zinc oxide and 3.0 lbs. of the above paste and mix the two until a uniform, smooth powder, free from lumps is obtained. An emulsion is prepared from this powder by dispersing 60 grams of it in 150 ml. of dry cleaners intermittently or pound of dry clothes is naphtha and adding to this tation 1000 ml. of hot water. water-in-oil type emulsion hours.

We then load a commercial e. g., 46 lbs. of rainwear with an absorbefacient dry mixture with vigorous agiwhich is stable for several dry cleaning washer with garments which are cleaned cleaners naphtha according to established technique. The detergent solution is then removed and the washer charged with fresh solvent. Then 92 fluid ounces, or about two ounces per pound of garments, of the emulsion specified is added by pouring the emulsion slowly onto the cylinder of the Washer while it is revolving. The washer is then run for 20 minutes after which garments are removed, extracted and dried. The same technique is applicable to garments which have been dry cleaned in solvents containing other absorbefacients, soaps and surface active materials.

For the purposes of this invention, the term dry cleaning solvent may be regarded as embracing the various petroleum solvents such as dry cleaners naphtha, and the like, as well as synthetic solvents such as carbon tetrachloride, trichloroethylene and perchalorethylene. The nullifying agent, broadly, is a metallic compound or salt which is adaptedto be decomposed by a heat such as that of the dry cleaners pressing operation, into a water insoluble metallic compound, e. g., into a hydrated metallic oxide. Aluminum acetate is a very common example of a material of this type. For purposes of this invention, zinc, zirconium, cobalt and lead may be classed as typical of the metals which are general equivalents of aluminum. Other weak organic acids such as formic and propionic may be combined with such metals to provide wather soluble salts which may be used in a fashion similar to the aluminum acetate. Suitable metallic alcoholates may also be used, such as altuninum isopropoxide, aluminum propoxide and other such alcoholates.

We have found that heating or pressing the cloth after final treatment is important to obtain a degree of water repellency suitable for customer acceptance and, within limits, the hotter the cloth is heated, the better the repellency. For example, if the cloth is treated and then dried at a temperature of F. to F., as is normally used in the tumbling or drying operation, the repellency will be very poor. However, if the cloth is pressed on a conventional finishing press where the temperature will probably be around 200 to 220 F., a considerable improvement in repellency will be obtained. Furthermore if the cloth is pressed on a so-called hot head press where the steam-heated head comes in direct contact with the cloth and the temperature may reach as high as 250 to 300 F., a still further improvement in repellency will be obtained.

In general, it is desirable to apply these nullifying compounds to the fabric in such proportions that, after drying, substantially 0.1% to 1.5% compound by weight is deposited on the fabric in dry form. If a water solution of the compound is employed, as we consider preferable, the solution should have a concentration of substantially 2V2% to 7 /&% compound in water, by weight. The concentration in water solution should be kept within the limits specified, as too low a concentration will necessitate the absorption of a quantity of solution which may be beyond the water tolerance of the fabric being treated, while too high a concentration will entail the use of such a small quantity of solution that it is difficult to obtain even absorption of the solution by the load of fabrics. Solution in the amount of 0.5 ounce to 3.0 ounces per preferably employed.

The type of emulsifying or dispersing agent used to disperse the aluminum acetate solution should be, first, cationic to avoid decomposition by the acidic aluminum acetate solution, second, decomposable by moderate heat to avoid adding a second wetting agent while attempting to neutralize the one already on the fabric and, third, characterized by the proper combination of hydrophilic and hydrophobic properties, or oil and water solubilities, to provide suitable emulsifying characteristics.

The compounds possessing all are the salts of long chain organic amines and volatile organic acids, for example the salts of formic, acetic or propionic acids and stearyl amine, distearyl amine, palmityl diethyl amine, the reaction product of one mole of stearic acid with one mole of ethylene diamine, and the amino esters obtained by condensing a fatty acid with a hydroxy amine such as triethanol amine. The

This forms a heavy, white,

of these characteristics the dry cleaner at present solvent to provide a employed.

The treatment may be applied to garments which are of the permanent water repellent type or to garments which for weatherproofing in addition to dry cleaning. In the latter two cases, it is necessary to impregnate the fabrics with wax, which may also be done to insure water repellency even to the permanently water repellent gartaining in solution paraflin wax or an equivalent hydrophobic material such as scale wax, microcrystalline wax, japan wax, carnauba wax, vegetable waxes and various mixtures thereof. While the wax may be dissolved in the solvent to which the nullifying compound is were previously treated to be permanently water repellent. On the other hand, any desired specialized water repellent material or technique of application may be utilized.

Finally the garments are dried, as by tumbling at a temperature, such as substantially 130 to 150 B, after which they are pressed by an iron or press which is heated to a temperature above 200 F. and is perhaps as much as a hundred or more degrees higher. After these finishing operations, the garments are water repellent.

Having described our invention, we claim:

1. The method of dry cleaning fabrics which are weatherproof or to be weatherproofed without impairing the water repellency thereof, said method comprising,

pound which includes a group consisting of aluminum, zinc, zirconium, cobalt and lead.

2. The method of dry cleaning fabrics which are weatherproof or to be weatherproofed without the water repellency thereof,

vent of the class consisting of naphtha, carbon tetrachloride, trichlorethylene and perchlorethylene and a surface active dry cleaning detergent of the class consisting of mahogany sulfonates, the soaps formed palmitic, oleic and stearic earth, hydroxides, ammonium, amines and alkanolamines, sulfated and sulphonated atty alcohols and alkylaryl sulphonates, .and further reating said fabric with a dry cleaning solvent of the type pecified which contains a heat unstable compound which ncludes a metal of the group consisting of aluminum, inc, zirconium, cobalt and lead to deposit 0.5-1.5 of aid compound upon the fabrics.

3. The method of dry cleaning fabrics which are which includes a metal of the group consisting of aluminum, zinc, zirconium, cobalt and lead and decomcontaining compound by pressing said fabrics at a temperature in excess of 200 F.

4. The method of dry cleaning fabrics without sacrificing the water repellency thereof, said method comlauric, palmitic, oleic and stearic acids with alkali and alkaline earth, hydroxides, ammonium,

aluminum, zinc, zirconium, ing said fabrics with a Weatherproofing material of the class consisting of parafiin and equivalent hydrophobic materials.

5. The method of dry cleaning fabrics without sacrificing the water repellency thereof, said method comprising, cleaning the fabrics in a mixture of a thereof.

6. The method of cleaning fabrics which are weatherproof or to be weatherproofed without impairing the water repellency thereof, said method comprising, cleaning the fabrics in a mixture of solvent of the class soluble salt of a metal of the group consisting of aluminum, zinc, zirconium, cobalt and lead, in the presence of stearyl amine as an emulsifying agent, and thereafter applying heat to said fabrics in the pressing operation which is conventional in a dry cleaning process.

7. The method of cleaning fabrics which are weatherproof or to be weatherpoofed without impairing the water repellency thereof, said method comprising, cleaning the fabrics in a mixture of a dry cleaning solvent of the class consisting of naphtha, carbon tetrachloride, trichlorethylene and perchlorethylene and a surface active dry cleanclass consisti rics vgitg a? emulsion in;dry cleaxgng solvent off the typei References Cited in the file of this patent speci e o a uminum acetate in t e presence 0 a steary amine as an emulsifying agent, and thereafter applying UNITED STATES PATENTS heat to said fabrics in thepressing operation which is con- Number Name Date ventional in a dry cleaning process. 5 1,990,691 Hatfield Feb. 12, 1935 Y 2,087,237 Bolton July 20, 1937 2,181,691 Nov. 28, 1939 2,323,387 2,345,142 Muller Mar. 28, 1944 

1. THE METHOD OF DRYING CLEANING FABRICS WHICH ARE WEATHERPROOF OR TO BE WEATHERPROOF WITHOUT IMPAIRING THE WATER REPELLENCY THEREOF, SAID METHOD COMPRISING, CLEANING THE FABRICS IN A MIXTURE OF A DRY CLEANING SOLVENT OF THE CLASS CONSISTING OF NAPHTHA, CARBON TETRACHLORIDE, TRICHLORETHYLENE AND PERCHLORETHYLENE AND A SURFACE ACTIVE DRY CLEANING DETERGENT OF THE CLASS CONSISTING OF MAHOGANY SULFONATES, THE SOAPS FORMED BY LAURIC, PALMATIC, OLEIC AND STEARIC ACIDS WITH ALKALI AND ALKALINE EARTH, HYDROXIDES, AMMONIUM, AMINES AND ALKANOLAMINES, SULFATED AND SULPHONATED FATTY OILS AND THEIR SALTS, SULFATED FATTY ALCOHOLS AND ALKYLARYL SULPHONATES, AND FURTHER TREATING SAID FABRIC WITH A DRY CLEANING SOLVENT OF THE TYPE SPECIFIED WHICH CONTIANS A HEAT UNSTABLE COMPOUND WHICH INCLUDES A METAL OF THE GROUP CONSISTING OF ALUMINUM, ZINC, ZIRCONIUM, COBALT AND LEAD. 